With water problems becoming more and more serious on a global scale, the competition in water business is on the increase worldwide, considering the market of water business as a huge one. In Middle Eastern countries which do not have surface water, such as rivers, or ground water, as water sources, or in regions within the country where a drought risk is high, seawater desalination technologies for securing water sources have been introduced, and large-scale seawater desalination plants have been installed.
The dominant conventional seawater desalination technology is an evaporation method in which seawater is first heated and evaporated and then condensation and recovery are performed. In recent years, on the other hand, a method using an RO (reverse osmosis) membrane (hereinafter referred to as “reverse osmosis membrane”) has been gaining in popularity from the standpoint of economic efficiency.